I am using Windows 10, a Master xy-540p vinyl cutter, and a Tripplite USA-19HS USB serial adapter. I found info on exporting hpgl files to the plotter and it worked, until it got almost done and cut a diagonal line through the entire project. I adjusted the settings, and this time it stopped plotting halfway through. Adjusted again, and it loses its place and plots in the wrong locations. I get one of the three errors every time I attempt to plot. Any information would be helpful. I would like to use Inkcut, but didn't find support for Windows. 

Sorry, only just read this.  If you haven't already done so I suggest you read the thread on this forum called "Vinyl cutter - when using export/plot extension cuts as it returns to origin".  You are not the only person to have had this problem and there is a work around.

check out this thread: https://inkscape.org/forums/cutplot/hpgl-output-goes-crazy/#c12819 seems like more of us are having similar issues. Another user found that 0.925 generates working HPGL and I can confirm that it is much better on my plotter!